Measurement Computing UL for NI LabVIEW - Manual (Page 44)

Universal Library Virtual Instruments (VIs) Signal conditioning VIs
ACnvPrDt.VI
Changed R3.3 RW (MOD)
Converts the raw data collected by APretrFg.VI or APretrBg.VI. APretrBg.VI and APretrFg.VI can return
either raw A/D data or converted data depending on whether or not the CONVERTDATA option was used.
The raw data as it is collected is not in the correct order. After the data collection is completed it must be
rearranged into the correct order. This VI correctly orders the data, starting with the first pretrigger data point
and ending with the last post-trigger point.
Change at revision 3.3 to support multiple background operations.
Inputs: BoardNum [U32] - The board number assigned when installed with InstaCal. Can
be 0 to 100.
PreTrigCount [I32] - Number of pre-trigger samples
TotalCount [I32] - Total number of A/D samples that were collected
DataArray [U32] - Data and channel tags
Outputs: DataArray [U32] - Converted data
ChanTags [I16] - Channel tags if available
ErrCode [I32] - Error code. See ErrMsg.VI
Arguments:
BoardNum The board number associated with a board when it was installed with InstaCal. The
specified board must have an A/D. Can be 0 to 100.
PreTrigCount Number of pre-trigger samples.
TotalCount Total number of A/D samples that were collected.
DataArray (In) Array of raw samples that require ordering.
DataArray (Out) Array of converted samples ordered with oldest samples first.
ChanTags Array of channel tags, if available.
ErrCode Error code returned from the Universal Library. Zero if no error occurred. Use the
ErrMsg VI to convert ErrCod e into a readable string.
Notes:
When you collect data with APretrFg.VI or APretrBg.VI and you don't use the CONVERTDATA option, you must
use this VI to convert the data after it is collected. There are cases where the CONVERTDATA option is not
allowed—for example, if you use the BACKGROUND option with APretrBg.VI or APretrFg.VI. In those cases,
use this VI to convert the data after the data collection is complete.
12-bit A/D boards: On some 12-bit boards, each raw data point consists of a 12-bit A/D value with a 4-bit
channel number. This VI separates the two and puts the A/D value into the
DataArray , and the channel number
into the ChanTags array. Upon returning from APretrBg.VI or APretrFg.VI, DataArray contains only 12-bit
A/D data.
16-bit A/D boards: This VI is used with 16-bit A/D boards only corrects the order of the data. No channel
tags are returned.
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